When, as recorded in the Potthapala Sutra, the Buddha refused to answer the questions "Is the world eternal? Is the world not eternal? Is the world finite? Is the world infinite?" he expressed something more than mere contempt for the futility of the logical self-torture of the intellect. For in his explanation of this refusal, he affirmed by implication that philosophy stood on a higher rung than mysticism. He said: "These questions are not calculated to profit, they are not concerned with the Dharma, they do not redound to right conduct nor to detachment, nor to purification from lusts, nor to quietude, nor to tranquillization of the heart, nor to real knowledge, nor to the insight of the higher stages of the Path, nor to Nirvana." Observe that these reasons are quite obviously placed in an ascending order according to their importance, because they begin with external conduct and end with Nirvana. And observe further that insight is not only placed higher than peace but actually said to belong to the higher stages of the Path. And observe finally that insight is placed only one stage below Nirvana, to which in fact it leads.
-- Notebooks Category 20: What Is Philosophy? > Chapter 4: Its Realization Beyond Ecstasy > # 204